CH455H

CH455 is a digital tube display driver and keyboard scan controller IC. CH455 integrates an internal clock oscillator circuit, capable of dynamically driving 4-digit numerical display tubes or 32 LEDs, while also supporting 28-key keyboard scanning. CH455 exchanges data with MCUs and other devices via a 2-wire serial interface consisting of SCL and SDA.

Key features

• Integrated display current drive stage: segment current ≥25mA, digit current ≥160mA
• Dynamic display scan control, supports 8×4 or 7×4, directly drives 4-digit 7-segment displays or 32 LEDs
• Internal current limiting with 8-level brightness control via duty cycle setting
• Integrated 28-key keyboard controller based on 7×4 matrix keyboard scan
• Built-in pull-down resistors for key state input with integrated debounce circuit
• Active-low keyboard interrupt, key release flag bit for querying key press and release events
• High-speed 2-wire serial interface, clock speed 0 to 4MHz, compatible with I²C bus, pin-saving
• Integrated POR, supports 2.7V～5V supply voltage
• Low-power sleep mode with wake-up via key press or command
• Integrated clock oscillator circuit, no external clock or oscillator components required, enhanced noise immunity
• Available in DIP18, SOP18, and SOP16 lead-free packages, RoHS compliant, partially pin and function compatible with CH450